PORT ANGELES – Enterococcus bacteria in marine water samples from the mouth of the Elwha River spiked Tuesday but returned to non-detectable levels on Thursday, according to the state Department of Ecology’s BEACH program.
The phenomenon coincided with Ecology personnel’s expectations.
Because Enterococcus usually returns to safe levels quickly, the beach remained open to swimming while more samples were tested, said Jessica Archer of Ecology.
Enterococcus can cause intestinal disorders, skin rashes, upper respiratory infections and other illnesses.
Children and elders may be more vulnerable to it.
Three sampling sites were tested for both Enterococcus and fecal coliform bacteria -both indicators of the presence of fecal matter.
The Enterococcus samples were all less than 10 parts per million, Archer said, and the fecal coliform samples were all below one colony forming unit per 100 milliliters.
“These are lowest possible results,” Archer said.
Archer said pathogens and bacteria in marine waters can come from both shore and inland sources.
Shore sources can include swimmers, boats, marine mammals, birds and other wildlife.
Inland sources can include stormwater runoff, sewer overflows, failing septic systems, and feces from livestock, pets and wildlife.
“We often observe high bacteria results following rain,” Archer said.
The Beach Environmental Assessment, Communication and Health program – or BEACH – recommends avoiding contact with marine waters for 48 hours after rainfall.
“When we find a beach that has continuous high counts indicating a chronic bacteria source, we can use methods such dye-testing nearby septic systems to identify the cause and work to fix the problem,” Archer said.
“It is much more difficult to identify if the high bacteria are coming from wildlife or pets.
“In that case, you would need to use molecular techniques that can be quite costly.”
To learn the latest results for the Elwha and other saltwater beaches, visit the BEACH Web site, www.ecy.wa.gov/programs/eap/beach/.